The timeline of .hack nears it’s final stages.
.Hack originally started off as a brilliant anime known as .hack//sign, where Tsukasa has lost all his “her” memories, ending up trapped within “The World with no way of logging out and returning to the real world.
Synopsis Taken from myanimelist.net
A young wavemaster, only known by the alias of Tsukasa, wakes up in an MMORPG called The World, with slight amnesia. He does not know what he has previously done before he woke up. In The World, he is suspected to be a hacker of the Crimson Knights, as he was seen accompanying a tweaked character in the form of a cat. Unable to log out from the game, he wanders around looking for answers, avoiding the knights and other players he meets along the way.
As Tsukasa explores The World, he stumbles upon a magical item that takes the form of a ‘guardian’, which promises him protection from all harm. Subaru, the leader of the Crimson Knights, along with several other players who became acquainted with Tsukasa, set out to investigate why Tsukasa is unable to log out, and attempt to get to the bottom of the problem before it gets out of hand.
Under this timeline comes the original .hack games for the PS2. [Infection, mutation, outbreak, quarantine.] Which brings into light the legendary .hackers and the future evolution of the PC, Kite. While this takes place in the same timeline as sign, the events and infection that happens in the games does not happen in sign.
At the beginning of .hack//Infection, Kite’s friend Orca invites him to play The World. In the first dungeon they visit, they encounter a girl in white being chased by a monster with a red wand. The girl attempts to entrust an item to Orca but the monster attacks him and The World’s servers crash. Kite discovers that Orca has fallen into a coma following the attack and resolves to discover why. Meeting BlackRose at the Chaos Gate, they go to a cathedral area where they are attacked by a powerful monster. The legendary player Balmung appears and defeats it but it revives as a Data Bug. The Book of Twilight, the item that the girl gave to Orca, activates and gives Kite the Twilight Bracelet. The Bracelet uses Data Drain on the monster, allowing Balmung to kill it. However, Balmung accuses Kite of causing the viral infection spreading through the game and leaves. Kite and BlackRose decide to team up to help the coma victims. After investigating a number of leads, Kite and BlackRose track down the monster that put Orca into a coma. They defeat the monster, Skeith, but it transforms into a larger enemy called Cubia which they escape from.
In .hack//Mutation, the two encounter Lios, a system administrator, who declares Kite’s Bracelet to be an illegal power. He attempts to delete Kite’s character data but fails because of a mysterious encryption. The hacker Helba intervenes and convinces Lios to observe for the time being. Lios directs them to an area where they find Innis, a monster with the same powers as Skeith. Upon defeating Innis, Kite receives an e-mail from the girl in white, who is actually an AI called Aura. They travel to an area to meet her but are confronted by Cubia, whom they repel with difficulty.Short on leads, they contact an information broker named Wiseman who is intrigued by Kite’s Bracelet. He suggests that Skeith and Innis are based on the Cursed Wave, an antagonistic force featured in the Epitaph of Twilight, an epic poem that forms the basis of The World. He helps grant them access to Net Slum, a place known as paradise for hackers and wandering AIs. Upon arrival, they are attacked by Magus, another Cursed Wave monster. They manage to defeat it, but when they return to the Root Town, they discover that the extensive corruption has spread to The World’s main servers and the real world.
Balmung finally decides to join Kite in .hack//Outbreak, after realizing that he cannot halt the infection on his own. BlackRose reveals to Kite that her brother fell into a coma under similar circumstances as Orca, which renews both their determination. Wiseman formulates a plan to combat the Cursed Wave, enlisting the help of Helba. Their teamwork destroys Fidchell but the aftermath causes networks to malfunction in the real world.Aura contacts Kite again, but their meeting is cut short by the reappearance of Cubia. Lios, observing Cubia’s power, agrees to join Kite, Helba, and the others to combat the Cursed Wave. Operation Breakwater begins as the team pool their resources to defeat Gorre, with no repercussions in the real world.
Server instability aborts a planning meeting at the start of .hack//Quarantine. Helba replaces the server with a copy of Net Slum to bypass this problem.At the bottom of a dungeon, Kite encounters Mia, a member of his party with a feline avatar. However, Mia is revealed to be Macha, a member of the Cursed Wave, whom he defeats with reluctance. Cubia assaults Kite’s team once again, even more powerful than before. They fend him off but are unsure if they will fare so well the next time, based on its rate of growth. Operation Orca, on the other hand, is a success as they destroy the next Wave, Tarvos. Kite seeks the advice of Harald Hoerwick, the creator of the game, who survives beyond death through his AI incarnations. Aura appears and advises that Cubia is the shadow of Kite’s Bracelet. Cubia ambushes them and destroys the AI Harald. In their final battle, Kite recalls Aura’s advice and has BlackRose destroy the Bracelet, causing Cubia to fade away. Lacking the Bracelet, the final Wave member, Corbenik, attacks the party in Net Slum Root Town. With the aid of the spirits of the coma victims, Kite succeeds in penetrating Corbenik’s barrier. Aura sacrifices herself to end the battle, restoring the network to normal and reviving all the coma victims.
After the crisis from the first games “The World” was shut down and brought back as R:2 Revision, which brings us to the Roots/G.U./Quantum timeline. Roots is a pre to the G.U. games for the PS2. Which takes place before the birth of Haseos hatred.
After the destruction of “The World” in 2015, CC Corporation rebuilt the game using data from what was previously to be another game. “The World R:2” was then released in 2016. A newcomer to the game, Haseo, is instantly PKed and then revived by a mysterious man known as Ovan. With the problem of PKs occupying the game, Haseo soon after receives help from a female Harvest known as Shino. Amidst curiosity and confusion, Haseo is lead to joining the guild known as the Twilight Brigade. The guild that searches for the legendary object known as the “Key of the Twilight”. Set before the .hack//G.U. game.
In his first adventure in The World R:2 the Adept Rouge Hasep was attacked by PKers but saved by a mysterious player named Ovan. Eight months later Haseo emerged as a powerful PKKer known as the “Terror of Death”, hunting for a strange PKer known only as Tri-Edge who had placed his close friend Shino into a coma six months earlier. Finally encountering Tri-Edge, Haseo was defeated by a strange attack called Data Drain. This attack reset his character back at level 1, however it also awoke a strange power that had been sleeping deep inside of him. This power, the ability to summon an entity known as Skeith drew the attention of a secret organization known as G.U.. As a new member of G.U. Haseo swore to find the truth of what was occurring in The World and find the truth about Tri-Edge.
The players of The World are in trouble as the AIDA problem becomes more dangerous. Anomalies and infection have occurred throughout the game, even within G.U. itself. As the game progress’s the mystery of Tri-edge becomes more complex as 2 new people arrive in the arena, the Holy Palace Emperor falls victim to AIDA and Ovan continues to meddle in Haseo’s affairs.
Anomalies and infections are growing in The World R:2 and spreading across the Network. While Haseo and his friends figure out a way to defeat Ovan, a new danger is growing.
After the events of G.U. “The World” was shut down once again and brought back again, lol wtf. Leading into the .hack//link game/manga as well as Quantum,”The World” R:X.
The story takes place in the year 2020, three years after the events of .hack//G.U.. The story will take place not only in the new version of “The World” known as “The World R:X” but in the real world as well. The lead character is a middle school student named Tokio Kuryuu. He lives a normal life as a gamer until a mysterious girl named Saika Amagi transfers to his school. She takes Tokio to the school rooftop one day and sends his consciousness and real body into The World R:X, where Tokio begins to discover that time for some characters, and even the history of The World itself, are going haywire; for instance, Tsukasa is turning back into his previous cold mannerisms, and Haseo is being cold-hearted and obsessive about finding and killing Tri-Edge.
As for Quantum, very little to nothing at this point is known about it. Other than the fact that it takes place within “The World” R:X. Being that Kite himself is in this version as well as AzureKite. That makes 3 fucking kite PCs in one timeline. The release of the first OVA is planned for 11/27
The Evolution of Kite.
The Original – Age 
Infection – Quarantine
Shugo – Age 
Legend of the twilight Bracelet
AzureKite – Aura’s Protector
The Original – Age 
The Original – Age 
.Hack//Link – Xth Form
Sora – Age [Unknown]
Sidenote – She is a female version of kite.
Finally, Quantum may be our last sight of .hack. Production of the games was said to have ceased after link by the developers at CyberConnect2. However that being said, it was only the games mention that will no longer be in production. So I’m hoping here myself that the animes will continue, although highly doubtful.